Efficacy of Hangeshashinto in the Prevention of Chemotherapy-Induced Diarrhea: A Systematic Review and Meta-Analysis

Hangeshashinto has attracted attention owing to its potential to prevent chemotherapy-induced diarrhea. However, studies on the efficacy of Hangeshashinto have had conflicting results. Evaluating the efficacy of Hangeshashinto may contribute to reducing the use and adverse events caused by drug therapy for chemotherapy-induced diarrhea. Medical Literature Analysis and Retrieval System Online (MEDLINE), were searched to retrieve all the relevant studies. Randomized controlled trials (RCTs) comparing the administration of Hangeshashinto with that of other treatments in patients with cancer receiving chemotherapy were included. The primary outcome was severe (grade 3-4) diarrhea assessed using the Common Terminology Criteria for Adverse Events. The secondary outcome was mild (grade 0-2) diarrhea. Out of 324 records identified, three studies were selected for the meta-analysis. Irinotecan was used for chemotherapy in all these studies. Hangeshashinto did not reduce the incidence of severe diarrhea compared with other treatments (risk ratio (RR) 0.40, 95% confidence interval (CI) 0.11-1.41, P = 0.15; low-quality evidence). Moreover, Hangeshashinto did not reduce the incidence of mild diarrhea (RR 1.35, 95% CI 0.872.09, P = 0.18; low-quality evidence). However, in the subgroup analysis compared with no treatment, the Hangeshashinto group had a significantly lower incidence of severe diarrhea (RR 0.17, 95% CI 0.03-0.88, P = 0.03; low-quality evidence). At present, insufficient evidence exists to support the claim that Hangeshashinto prevents diarrhea caused by irinotecan-based chemotherapy.